Treatment of hydrocarbon oils



Jan. 31, 1961 A, c. CONDO, JR., ETAL 2,970,105

TREATMENT OF HYDROCARBON OILS Filed Aug. 11, 1958 ANHYDROUS HYDROCARBON METALLIC HALIDE on. PHAsE PPT, A FILTRATE A WATER souo PHAsE on. PHASE PPT. B FILTRATE B k I Q souo PHASE on PHASE AQ. PHASE on. HAsE WATER AQ. PHASE OIL PHASE .Ao. PHASE S'E AQ.PHASE ALBERT 0. 00mm, JR. JA MES B. HUNTER A TTES T: IN VEN TOR-9 AMP- 5 M ATTORNEY United States Patent TREATMENT OF HYDROCARBON OILS Albert C. Condo, Jr., Newtown Square, and James Hunter, Havertown, Pa., assignors to The Atlantic Refining Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Aug. 11, 1958, Ser. No. 754,271

7 Claims. (Cl. 208-495) This invention relates to the treatment of hydrocarbon oils. More particularly this invention relates to the treatment of all manner of liquid hydrocarbon products such as motor fuels, naphthas, kerosene, diesel fuels, fuel oils, lubricating oils, etc., whereby objectionable materials such as gumming and/or resinifying constituents, highly unsaturated compounds, asphaltic suspensoids, sulfur, oxygen and nitrogen compounds and other deposit, color, and odor forming materialsare substantially removed therefrom.

It is well known that petroleum oils obtained from different sources vary considerably as to their respective chemical and physical properties. It is equally well known that the various distillates obtained from pctroleum oils also exhibit properties unique to that particular distillate. Distillates obtained, for example, from cracking processes are usually characterized by unpleasant odors which odors are indicative of substances contained in the oil which may polymerize or resinify, thus forming materials which are objectionable from a commercial standpoint. These odoriferous substances which include sulfur, oxygen, and nitrogen compounds, alkynes, etc. are usually present in the'distillate products in relatively small amounts.

Heretofore the presence of these materials in distillate products, even in small amounts, was recognized and many processes have been developed to reduce the amount of or substantially eliminate these materials. Treatments of hydrocarbon oils with various reagents such as caustic soda, plumbite solutions, adsorbents, metallic oxides, etc. have been proposed in the prior art. One of the most commonly employed treatments of hydrocarbon oils therefrom is by agitation with strong sulfuric acid, and even fuming sulfuric acid. Such a treatment of a hydrocarbon oil, not only removes the undesirable materials contained in the oil but also substantially reduces the olefinic content of the oil, thus resulting in large volume losses of both oil and acid. In the case of cracked petroleum products, such a treatment results in a loss which is both excessive and uneconomical.

In addition to the reagents described above, many other attempts have been made to substitute other chemical compounds for sulfuric acid in the treatment of hydrocarbon oils. One class of compounds found particularly suitable for refining hydrocarbon oils are the anhydrous metallic chlorides such as stannic chloride, antimony chloride, aluminum chloride, ferric chloride, mercuric chloride, zinc chloride, etc.

An anhydrous metallic chloride which has been found to possess properties particularly desirable in a reagent for treating hydrocarbon oils is anhydrous titanium tetrato remove objectionable materials chloride. Titanium tetrachloride is a clear colorless liquid, M.P. 24.8 C., 8.1. 135.8 C. It is both water soluble and hydrocarbon soluble and forms addition compounds with sulfur, nitrogen, and oxygen compounds and also with other organic materials. It is this particular property which makes titanium tetrachloride :a most suitable reagent for treating hydrocarbon oils.

The use of metallic halides, such as titanium tetrachloride, as refining agents for hydrocarbon oils has long been recognized in the prior art (i e., see US. Patent No. 1,643,272 issued to T. Hellthaler, eptember 20, 1927). The usual methods of treating hydrocarbon oils with metallic chlorides according to the prior art have been to agitate the oil to be treated with a metallic halide, which may or may not be diluted with other materials, and then purify the treated oil with a water wash and/or a caustic wash. These previous methods were significantly deficient in that they failed to remove all or substantially all of the compounds contained in the oil, which would react with a metallic halide.

It is therefore an object of this invention to provide an improved process for the treatment of hydrocarbon oils using anhydrous metallic halides.

It is a further object of this invention to provide an improved process for the refining of hydrocarbon oils using a novel and unique process employing the action of anhydrous metallic halides and water.

It is a still further object of this invention to provide a new and improved process for the refining of hydrocarbon oils using anhydrous metallic halides and water in such a manner that the hereinabove mentioned problems of the prior artv are substantially overcome.

Other objects will become apparent as the description of this invention proceeds.

It is well known that the treatment of hydrocarbon oils with anhydrous metallic halides will result in the formation of a heterogeneous mixture comprising an oil phase and a solid phase which mixture when separated results in an oil phase and a solid precipitate. This oil may then be washed with either water and/or caustic soda, resulting in a purified oil product.

It has now been discovered in accordance with this invention that further amounts of solid material may be removed from this oil product by the addition of critical amounts of water to the oil prior to a water or caustic wash. The amount of water to be added to the oil is such that a maximum amount of solid material is preis added to the oil, no formation cipitated therefrom. This amount of water is a most necessary and critical aspect of this invention and heretofore unrecognized in the prior art. If less than the critical amount of water is added to the oil, obviously less than maximum amounts of thesolid material will be formed. Also, if slightly more than a critical amount of water is added to the oil, less than a maximum amount of solid material will be formed. If an excess of water of the solid material will occur.

This invention will be further understood by reference to the accompanying drawing wherein a hydrocarbon oil is treated with an anhydrous metallic halide thus causing the formation of an oil phase and a solid phase.

any convenient means such as filtration, centrifuging, decantation, etc. to form an oil phase (precipitate A). To filtrate A there is added an amount of water sutficient to cause the formation of .a

phase (filtrate A) and a solid second heterogeneous mixture composed of an oil phase and a solid phase. This mixture is separated into an oil phase (filtrate B) and a solid phase (precipitate B). Filtrate B is then washed with a dilute aqueous caustic solution forming an oil phase and an aqueous phase. The oil phase is separated from the aqueous phase and washed with water and finally a refined oil product is separated and recovered.

As stated above, in the practice of this invention, a hydrocarbon oil is treated with an anhydrous metallic halide. These metallic halides may be depicted by the general formula MeX where Me represents a metal selected from the group consisting of antimony, tin, iron, aluminum, silicon, zinc, and titanium, X represents a halogen selected from the group consisting of fluorine, chlorine, bromine, and iodine, and n is an integer from 2 to 5. A preferred class of anhydrous metallic halides to be used in this invention are the anhydrous metallic chlorides and a preferred anhydrous metallic chloride to be used in this invention is anhydrous titanium tetrachloride.

The amount of anhydrous metallic halide to be used in treating a hydrocarbon oil according to the process of this invention may vary over wide limits; however, for reasons of practicality and economy an amount ranging between about 0.1 to about 5.0 volume percent of anhydrous metallic halide based on the volume of oil to be treated has been found sufiicient. A preferred range of anhydrous metallic halide to be used in the practice of this invention is that ranging between about 0.25 to about 1.0 volume percent of the hydrocarbon oil to be treated.

After the treatment of the hydrocarbon oil with an anhydrous metallic halide to form a heterogeneous mixture composed of an oil phase and a solid phase which is then separated to produce a filtrate and a precipitate, the filtrate is treated with an amount of water suflicient to form a maximum amount of a solid phase in a second heterogeneous mixture. The exact amount of water used to cause the formation of maximum amounts of this solid phase will vary with the amount of anhydrous metallic halide used and with each particular hydrocarbon oil to be treated. Therefore, no specific amounts of water to be used in this portion of the process may be stated. The amount of water, however, is determined by titration with water of a small portion of the oil phase obtained after the initial treatment with an anhydrous metallic halide. The amount of water required to produce a maximum amount of precipitate, found in this preliminary titration of a measured portion of the hydrocarbon oil is then used as a basis for calculating the was treated with about 50 cc. of water.

total amount of water necessary to treat the bulk of the hydrocarbon oil to be refined according to the method of this invention.

The solid phase obtained both from the treatment of a hydrocarbon oil with an anhydrous metallic halide and from the subsequent treatment with a specific amount of water may be hydrolyzed with an excess amount of water and substantially decomposed to form an oil phase and an aqueous phase containing a small amount of 7 solid material. The oil phase obtained by such a hydrolysis is highly colored and possesses a sour odor. This colored and odoriferous oil is composed of materials which apparently are capable of forming addition compounds with an anhydrous metallic halide and, as such, are removed as precipitates when the original hydrocarbon oiland filtrate obtained therefrom are treated with ananhydrous metallic halide and a critical amount of water respectively.

' In a specific embodiment of this invention, a hydrocarbon oil is treated with about 0.25 to about 1.0 volume percent of anhydrous titanium tetrachloride to cause the formation of a heterogeneous mixture composed of an ture when separated from the solid phase is treated with" an amount of water suflicient to form a second heterogeneous mixture comprising an oil phase and a solid phase. The oil phase from the second heterogeneous mixture upon separation therefrom is then washed with about 30 to 40 volume percent of 5 percent aqueous sodium hydroxide solution and the oil is then washed with about 5 to 15 volume percent of water until the water washes are neutral to litmus. Upon separation of the oil from the water wash a refined oil product is obtained.

This invention will be further understood from the following examples which are intended to be illustrative only and are not to be constituted as limitative.

EXAMPLE I A 1000 cc. sample of a cracked naphtha was agitated with one volume percent (10 cc.) of titanium tetrachloride. A heterogeneous mixture was formed composed of a red colored oil phase and a solid phase which upon forming was a deep red but slowly changed to a dark amber and finally to black. The oil phase and the solid phase were separated by filtration. divided into three equal portions (the second and third portions to be used in Examples II and Ill respectively).

The filtrate thus obtained was washed with 25 cc. of water and there was produced an' oil phase and an aqueous phase. This oil when separated from the water possessed an amber color.

The solid phase obtained by this treatment of thecracked naphtha with anhydrous titanium tetrachloride This water treatment produced a heterogeneous system comprising an oil phase, dark amber in color, and an aqueous phase containing a small amount of suspended solids. The oil phase was separated therefrom and analyzed for elemental sulfur and hydrocarbon composition as measured by a mass spectrometer. are presented in Table I.

EXAMPLE II The second portion of the filtrate obtained in Example I was placed in a 500 cc. graduated cylinder. To this oil, Water was added drop-wise. After the addition of each drop the graduated cylinder was inverted several times to insure complete contact of the water and oil. The solid phase thus produced was allowed to settle and the amount of solid materials so formed was noted.

The above procedure was continued until 1.6 cc. of water had been added. This amount of water resulted in the formation of a maximum amount of solid material. The criticality of this amount of water was proven by adding one ortwo more drops of water and noting that the amount of solid material decreased.

EXAMPLE III To the third portion of the filtrate obtained in Example I there was added 1.6 cc. of water (this amount of water beingsufficient to form a maximum amount of solid material as proven by Example II). The oil phase and the solid phase were separated by filtration and the The results of these analyses filtrate was washed with 75 cc. of a 5 percent aqueous sodium hydroxide solution and separated. Upon separation of the oil phase and aqueous caustic phase the oil was then washed with several portions of cc. of water until the water washes were, neutral to litmus and a colorless refined oil product was recovered.

The solid phase obtained was treated with about 5 cc. of water. This produced an amber oil phase and an aqueous phase containing a small amount of suspended solids. The oil phase was separated therefrom and analyzed for elemental sulfur and hydrocarbon composition by means of a mass spectrometer. The results of these analyses are presented in Table I.

The filtrate was Table I COMPOSITION OF PRODUCTS FROM TREATING gn tcnnn NAPHTHA WITH ONE VOLUME PERCENT Oil From Oil From Hydrol- Hydrol- Oil Oil ysis of ysis of Product Product Component Charge Solid Solid From From Material Material Example Example of of I III Example Example I III Paraffins (cc.) 20. 9 0. 6 1.0 Olefins (cc.) 44.3 0.7 1.3 Cyclo-Paraflins (cc.) 9. 6 0.5 0. 7 Aromatics (00.) 19.3 1.0 1.2

CODA 1 (00.).. 5.9 0.2 0.3

Total V01. (cc.) 100 3 4.

Sulfur (gm.) 0.162 0.025 0.018 0.119 Color Amber Amber Colorless Odor Sour Sour Sweet 1 Cycloolefins, diolefins, acetylenes.

It will be recognized that the treatment of a hydrocarbon oil with anhydrous titanium tetrachloride in Example I is similar to processes of the prior art wherein a hydrocarbon oil is treated with an anhydrous metallic halide; whereas the treatment of a hydrocarbon oil as shown in Example III is according to the method of this invention.

From the data presented in Table I, it is shown that hydrocarbon oils treated according to the present invention result in oil products which are colorless and possess a sweet odor. It is also shown in Table I that an additional 72 percent of the sulfur compounds contained in the original hydrocarbon oil are removed by the process of this invention.

We claim:

1. A process for refining hydrocarbon oils which comprises treating said hydrocarbon oils with an anhydrous metallic halide wherein an oil phase and a solid phase are formed, separating the solid phase from the oil phase, adding to the oil phase a critical amount of water, said amount of water having been previously determined by titration of an aliquot portion of the hydrocarbon oil to be treated with water until a maximum amount of precipitate is formed, which amount of precipitate is shown to be a maximum by the continuance of the titration of the aliquot portion of the hydrocarbon oil with water until the subsequent disappearance of the precipitate formed, to cause the formation of a second solid phase and an oil phase, separating said second solid phase from the oil phase, washing the oil phase with a dilute aqueous caustic solution to form an oil phase and an aqueous phase, separating the oil phase from the aqueous phase, washing the oil phase with water and recovering a refined oil product.

2. A process for refining liquid hydrocarbon oils which comprises treating said hydrocarbon oils with an anhydrous metallic halide of the general formula MeX water having been previously determined by titration of an aliquot portion of the hydrocarbon oil to be treated with water until a maximum amount of precipitate is formed, which amount of precipitate is shown to be a maximum by the continuance of the titration of the aliquot portion of the hydrocarbon oil with water until the subsequent disappearance of the precipitate formed, to cause the formation of a second solid phase and an oil phase, separating said second solid phase from the oil phase, washing the oil phase with a dilute aqueous caustic solution to form an oil phase and an aqueous phase, separating the oil phase from the aqueous phase, washing the oil phase with water and recovering a refined oil product.

3. A process for refining liquid hydrocarbon oils which comprises treating said hydrocarbon oils with a metallic halide of the general formula MeXn where Me is selected from the group consisting of aluminum, antimony, iron, silicon, tin, titanium, and zinc, X is selected from the group consisting of fluorine, chlorine, bromine, and iodine, and n is an integer from 2 to 5, in an amount ranging between about 0.1 to about 5 volume percent of the hydrocarbon oil wherein an oil phase and a solid phase are formed, separating the solid phase from the oil phase, adding to the oil phase a critical amount of water, said amount of water having been previously determined by titration of an aliquot portion of the hydrocarbon oil to be treated with water until a maximum amount of precipitate is formed, which amount of precipitate is shown to be a maximum by the continuance of the titration of the aliquot portion of the hydrocarbon oil with water until the subsequent disappearance of the precipitate formed, to cause the formation of a second solid phase and an oil phase, separating said second solid phase from the oil phase, Washing the oil phase with a dilute aqueous caustic solution to form an oil phaseand an aqueous phase, separating the oil phase from the aqueous phase, washing the oil phase with water and recovering a refined oil product.

4. A process according to claim 3 wherein the amount of metallic halide ranges between about 0.5 to about 1.0 volume percent of the hydrocarbon oil.

5. A process for refining hydrocarbon oils which comprises treating said hydrocarbon oils with anhydrous titanium tetrachloride wherein an oil phase and a solid phase are formed, separating the solid phase from the oil phase, adding to the oil phase a critical amount of water, said amount of water having been previously determined by titration of an aliquot portion of the hydro carbon oil to be treated with water until a maximum amount of precipitate is formed, which amount of precipitate is shown to be a maximum by the continuance of the titration of the aliquot portion of the hydrocarbon oil with water until the subsequent disappearance of the precipitate formed, to cause the formation of a second solid phase and an oil phase, separating said second solid phase from the oil phase, washing the oil phase with a dilute aqueous caustic solution to form an oil phase and an aqueous phase, separating the oil phase from the aqueous phase, washing the oil phase with water and recovering a refined oil product.

6. A process according to claim 5 wherein the amount of titanium tetrachloride ranges between about 0.1 to about 5.0 volume percent.

7. A process according to claim 5 wherein the amount of titanium tetrachloride ranges between about 0.5 to about 1.0 volume percent.

References Cited in the file of this patent UNITED STATES PATENTS 1,643,272 Hellthaler Sept. 20, 1927 2,721,833 Defoe et a1. Oct. 25, 1955 2,729,594 Alderson et a1. Jan. 3, 1956 2,756,185 =Brehm et a1 July 24, 1956 2,796,387 Schmidt June 18, 1957 

1. A PROCESS FOR REFINING HYDROCARBON OILS WHICH COMPRISES TREATING SAID HYDROCARBON OILS WITH AN ANHYDROUS METALLIC HALIDE WHEREIN AN OIL PHASE AND A SOLID PHASE ARE FORMED, SEPARATING THE SOLID PHASE FROM THE OIL PHASE, ADDING TO THE OIL PHASE A CRITICAL AMOUNT OF WATER, SAID AMOUNT OF WATER HAVING BEEN PREVIOUSLY DETERMINED BY TITRATION OF AN ALIQUOT PORTION OF THE HYDROCARBON OIL TO BE TREATED WITH WATER UNTIL A MAXIMUM AMOUNT OF PRECIPITATE IS FORMED, WHICH AMOUNT OF PRECIPITATE IS SHOWN TO BE A MAXIMUM BY THE CONTINUANCE OF THE TITRATION OF THE ALIQUOT PORTION OF THE HYDROCARBON OIL WITH WATER UNTIL THE SUBSEQUENT DISAPPEARANCE OF THE PRECIPITATE FORMED, TO CAUSE THE FORMATION OF A SECOND SOLID PHASE AND AN OIL PHASE, SEPARATING SAID SECOND SOLID PHASE FROM THE OIL PHASE, WASHING THE OIL PHASE WITH A DILUTE AQUEOUS CAUSTIC SOLUTION TO FORM AN OIL PHASE AND AN AQUEOUS PHASE, SEPARATING THE OIL PHASE FROM THE AQUEOUS PHASE, WASHING THE OIL PHASE WITH WATER AND RECOVERING A REFINED OIL PRODUCT. 